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Nonsense, of course, but it helps illustrate a point: You will need a computer password today, maybe a half dozen or more — those secret sign-ins that serve as sentries for everything from Amazon shopping carts to work files to online bank accounts. Just when you have them all sorted out, along comes another “urgent” directive from the bank or IT department — time to reset those codes, for safety’s sake. And the latest lineup of log-ins you’ve concocted won’t last for long, either. Some might temporarily stay in your head, others are jotted on scraps of paper and stuffed in a wallet. A few might be taped to your computer monitor in plain view (or are those are from last year’s batch? Who can remember?).